JPH09207338A - Recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable, high picture quality recording head by lessening the bulge of adhesive at the time of bonding a nozzle member and a glass substrate thereby preventing the flow of conductive ink from being blocked and suppressing the deformation and positional shift of nozzle member from the glass substrate thereby enhancing stability in the jet control of conductive ink. SOLUTION: The recording head comprises a nozzle member 23 having a nozzle hole 26 for jetting a conductive ink and a room 27 for boiling the conductive ink, a glass substrate 22 having a pair of electrode parts 24 disposed under the ink boiling room 27 in order to generate a bubble in the conductive ink, a wiring part 31 to be connected with the electrode parts 24, and an insulation layer 3 covering the wiring part 31 and the like, and an adhesive resin layer 2 for bonding the nozzle member 23 and glass substrate 22. The adhesive resin layer 2 is composed of a thermoplastic epoxy based resin and the insulation layer 3 is composed of a cyclorubber based photosensitive resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head that prints by attaching conductive ink ejected from nozzle holes to recording paper.

[0002]

2. Description of the Related Art In recent years, there have been increasing demands for higher speed printing and lower noise in printers, and in particular, ink jet printers have been attracting attention as satisfying these demands. The recording head system uses a so-called piezo effect, which is electromechanical energy conversion, a system that electrostatically attracts and ejects ink droplets, and a so-called thermal jet that generates Joule heat generates ink droplets. A device that discharges the liquid has been put into practical use. In particular, the bubble jet that uses Joule heat has a simple structure, and since the ink ejection parts can be arranged at a high density by using a thin film process or a semiconductor process, it is possible to improve the printing quality and achieve high-speed printing. Suitable to do.

A printhead used in a conventional printhead printer will be described below. FIG. 4A is a schematic plan view showing the structure of a conventional recording head, and FIG.
FIG. 4 is a schematic sectional view showing the structure of a conventional recording head. In FIG. 4, 21 is a conventional recording head, 22 is a glass substrate which is an insulator that can be used in a thin film process, 2
3 is a nozzle member made of a polyimide sheet in which a nozzle hole 26 and an ink boiling chamber 27 described later are formed, 24 is a pair of electrode parts patterned on the glass substrate 22 for heating and boiling the conductive ink, and 25 is An insulating layer laminated on the glass substrate 22, 26 is a nozzle hole that is a discharge port of the conductive ink formed in the nozzle member 23, and 27 is a conductive ink heated by applying a current to the pair of electrode portions 24. An ink boiling chamber in which bubbles are generated when boiled, 28 is a common ink chamber for supplying conductive ink to the ink boiling chamber 27, 2
Reference numeral 9 denotes an ink supply hole which is connected to an external ink tank and which is provided in the glass substrate 22 for supplying the conductive ink to the common ink chamber 28. Reference numeral 30 denotes an adhesive resin layer for joining the glass substrate 22 and the nozzle member 23. Reference numeral 31 denotes an electrode portion. A wiring portion in which a pattern is extended from 24 with the same electrode material, and 32 is a wiring portion 31.
It is an external connection terminal for connecting a signal generating unit (not shown) for applying a voltage between the pair of electrode units 24 via.

A conventional recording head constructed as described above
The manufacturing method of 21 will be described below. Glass substrate
Platinum or titanium electrode material having a thickness of 1 to 3 μm on 22
Photolithography is performed by stacking on the
Thus, the electrode portion 24 and the wiring portion 31 are formed. Wiring part
At the end of 31, the external connection terminal 32 is made of titanium and gold in this order.
After being vapor-deposited in, the wiring is photo-etched.
Next, silica (SiO _Two) Is laminated by the sputtering method.
Or by coating with polyimide
The insulating layer 25 having a thickness of approximately 2 to 4 μm is formed. More thin
After the film process, the glass substrate 2 is machined.
The ink supply hole 29 is formed by punching 2
You. The hole width of the ink supply hole 29 is about 0.3 mm,
As the processing method, ultrasonic processing or sand blasting
Etc. are used.

On the other hand, the nozzle member 23 has a thickness of 70-12.
A 0 μm polyimide sheet is coated in advance with a thermosetting epoxy adhesive to form an adhesive resin layer 30 having a thickness of 2 to 4 μm, and the common ink chamber 28 and the ink boiling chamber 2 are formed by a method such as excimer laser or chemical etching.
7. The nozzle holes 26 are sequentially processed. Ink boiling chamber 27
System is about 100 μm, and the system of the nozzle holes 26 is 30 to 30 μm.
50 μm. The nozzle holes 26 are
For example, they are arranged at intervals of 150 dpi (dot / inch) or 300 dpi. Nozzle member 23 obtained in the above process
Is aligned with the glass substrate 22, and is bonded with a thermosetting epoxy adhesive on the nozzle member 23 by applying pressure and heat. With respect to the thermosetting epoxy adhesive, joining is completed in 1 hour under a condition of a load of 1 kg / cm ² and a temperature of 160 ° C.

The operation of the conventional recording head 21 manufactured as described above will be described below. With respect to the recording head 21, the ink boiling chamber 2 is provided by the ink supply hole 29.
Conductive ink is supplied to 7. By applying a voltage to the pair of electrode portions 24 provided in the ink boiling chamber 27, the conductive ink between the electrode portions 24 is energized, and the ink temperature of the conductive ink rises and boils. ,
Create bubbles. By the generation of this bubble and the expansion of the bubble,
The pressure in the ink boiling chamber 27 increases, and the conductive ink is ejected as ink droplets to the outside by the nozzle holes 26.

[0007]

With this recording head,
When the nozzle member and the glass substrate are bonded to each other, as shown in FIG. 5, a phenomenon occurs in which the adhesive protrudes into the space of the common ink chamber and the nozzle boiling chamber other than the joint surface, and the adhesive protrusion 33 is formed. To be done. The adhesive that sticks out obstructs the flow of the conductive ink in the common ink chamber or the ink boiling chamber, causing defective ink supply or abnormal boiling, which prevents normal ink ejection operation and deterioration of the printed image. Occurs. In order to prevent this, when the thickness of the adhesive is reduced, the pressure and temperature of the adhesion are increased in order to sufficiently adhere the glass substrate and the nozzle member, and the protrusion of the adhesive is improved. I couldn't. Further, excessive heating and pressurization may cause deformation of the nozzle member, misalignment with the glass substrate, or cracking of the glass substrate, resulting in a decrease in yield in the manufacturing process. Therefore, there is a demand for preventing the yield from decreasing in the manufacturing process and reducing the protrusion of the adhesive.

According to the present invention, when the nozzle member and the glass substrate are joined, the protrusion of the adhesive is reduced to prevent the flow of the conductive ink from being obstructed, and the nozzle member is deformed and the position of the glass substrate is displaced. Therefore, it is an object of the present invention to provide a recording head which is improved in the stability of ejection control of the conductive ink by reducing the number of prints and has high image quality and excellent reliability.

[0009]

To solve this problem, the present invention provides a nozzle member having a nozzle hole through which conductive ink is ejected and an ink boiling chamber for boiling the conductive ink, and an ink boiling chamber. The nozzle member and the glass substrate are bonded to each other, and the glass substrate having a pair of electrode portions disposed below to generate bubbles in the conductive ink, a wiring portion connected to the electrode portions, and an insulating layer covering the wiring portion, and the nozzle member. A recording head having an adhesive resin layer, wherein the adhesive resin layer is made of a thermoplastic epoxy resin and the insulating layer is made of a cyclized rubber type photosensitive resin.

As a result, a thermoplastic epoxy resin such as a modified urethane adhesive or a modified epoxy adhesive having flexibility is used for the adhesive resin layer, and a cyclized rubber photosensitive resin having flexibility is used for the insulating layer. By using, it is possible to increase the step difference absorption capability of the adhesive surface on the glass substrate, and to join the nozzle member and the glass substrate with low weight,
Since the adhesive effect can be improved with a small amount of adhesive, it is possible to reduce the protrusion of the adhesive into the ink boiling chamber, the common ink chamber, etc., and obtain a highly reliable recording head with excellent print quality. be able to.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording head according to claim 1 of the present invention comprises a nozzle member having nozzle holes through which conductive ink is ejected and an ink boiling chamber for boiling the conductive ink,
A glass substrate having a pair of electrode portions arranged below the ink boiling chamber for generating bubbles in the conductive ink, a wiring portion connected to the electrode portions, and an insulating layer covering the wiring portion, a nozzle member and a glass substrate. A recording head comprising: an adhesive resin layer that joins with an adhesive resin layer, wherein the adhesive resin layer is made of a thermoplastic epoxy resin, and the insulating layer is made of a cyclized rubber-based photosensitive resin. Adhesion on a glass substrate by using a thermoplastic epoxy resin such as a modified urethane adhesive or a modified epoxy adhesive with flexibility for the resin layer and a cyclized rubber type photosensitive resin with flexibility for the insulating layer Since it is possible to increase the level difference absorbing ability of the surface, the nozzle member and the glass substrate can be bonded with a low weight, and the adhesive effect can be improved with a small amount of adhesive. An effect that it is possible to reduce the protrusion of the adhesive to the compartments and the like.

According to a second aspect of the present invention, there is provided a recording head according to the first aspect.
In the above, since the side surface portion of the wiring portion is formed in a bent line shape, the bonding area between the nozzle member and the glass substrate can be increased, and the bonding strength can be improved.

The recording head according to claim 3 of the present invention is
In Claim 1 or 2, The upper surface part of a wiring part is equipped with the structure which has a several recessed part, The nozzle member and a glass substrate are joined by the anchor effect of the adhesive resin layer by a several recessed part, and the adhesive strength. It has the effect of being able to improve.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a sectional view of a main part of a recording head according to a first embodiment of the invention. In FIG. 1, 1A
Is a recording head according to the first embodiment of the present invention. 22 is a glass substrate, 23 is a nozzle member, 24 is an electrode part, 26 is a nozzle hole, 27 is an ink boiling chamber, 28 is a common ink chamber,
Reference numeral 31 is a wiring section. Since these are the same as those in FIG. 4 of the conventional example, the same reference numerals are given and description thereof is omitted. The first embodiment is different from the conventional example in that the adhesive resin layer 2 is made of a thermoplastic epoxy resin and the insulating layer 3 is made of a cyclized rubber photosensitive resin.
In addition to increasing the step difference absorption capability of the adhesive surface on the nozzle 2, the nozzle member 23 and the glass substrate 22 can be joined with a low weight, and the adhesive effect can be improved with a small amount of adhesive. Boiling chamber 27 and common ink chamber 2
It has an effect that the protrusion of the adhesive to 8 and the like can be reduced.

The glass substrate 22 is a smooth substrate having a thickness of 1 mm for a thin film process and is used for thin film metallization.
The coefficient of linear expansion is 90 to 120 × E ^-7 / ° C. A conductive layer of platinum or titanium having a thickness of 1 to 3 μm is formed on the glass substrate 22 by a sputtering method. Next, the electrode portion 24 and the wiring portion 31 are formed on the entire surface conductive layer by using the photolithography technique. In order to remove the metallization of unnecessary portions, a hydrofluoric acid-based etching solution or a mixed solution of EDTA and hydrogen peroxide solution, ammonia, and water, as well as a method such as ion milling as a dry etching method can be used. Here, the line width of the electrode portion 24 that plays an important role in generating bubbles of the conductive ink is 20 to 30 μm, and the gap between the pair of electrode portions 24 is 3 to 6 μm. Next, the external connection terminal 32 is formed at the end of the wiring portion 31. After forming the electrode portion 24, the wiring portion 31, and the external connection terminal 32, the insulating layer 3 is formed. As the material of the insulating layer 3,
A negative type cyclized rubber resist often used in photoetching, for example, a micro resist (OMR83 or the like) commercially available from Tokyo Ohka is used. This resist has a property of causing a cross-linking reaction by being irradiated with ultraviolet rays and leaving as a pattern after development, and at the same time having high chemical resistance. Since the cyclized rubber resist is a cyclized natural rubber or isoprene rubber, it has flexibility. As a method of coating the insulating layer 3 on the glass substrate 22, a dip method may be used in addition to the spin coating method. After the spin coating, the prepolymerized cyclized rubber resist is dried at 90 ° C. for 30 minutes, exposed to ultraviolet light with a predetermined mask pattern, and developed with a developing solution to form the pattern of the insulating layer 3. afterwards,
It is dried at 110 ° C. for 30 minutes to scatter the developing rinse solution. Before forming the insulating layer 3, pre-coating with a silane coupling agent is performed to make the nozzle member 23 and the glass substrate 22.
It is also possible to prevent the peeling from. Next, the glass substrate 2
Ink supply holes 29 are formed in the second plate 2 by punching.

Next, a method of forming the nozzle member 23 in the recording head 1A according to the first embodiment of the present invention will be described. The nozzle member 23 is made of a polyimide sheet, has a thickness of 60 to 130 μm, and has a linear expansion coefficient of 2 × 10.
^-5cm / cm ° C, a resin with relatively small dimensional change is used. This is because the arrangement of the nozzle holes 26 is related to the ink landing accuracy itself during printing. First, an adhesive to be the adhesive resin layer 2 is applied on a polyimide sheet with a bar coater. As a material for the adhesive, it is preferable to use a urethane-based adhesive or a modified epoxy-based adhesive, which is highly flexible and chemically stable. As a urethane-based adhesive, PU-81 manufactured by Toagosei Kagaku Kogyo Co., Ltd.
00, modified epoxy adhesives include AS-60 manufactured by Toagosei Kagaku Kogyo. The thickness of the adhesive resin layer 2 is preferably 2 to 20 μm, more preferably 10 to 15 μm. Thereby, the nozzle member 23 and the glass substrate 2
No. 2 and the glass substrate 22 by the position adjustment while increasing the step absorbing ability on the adhesive surface in FIG.
It is possible to reduce the positional deviation between and. After forming the adhesive resin layer 2, the common ink chamber 28, the ink boiling chamber 27, and the nozzle hole 26 are sequentially processed by the excimer laser. Here, the excimer laser oscillates a laser in the ultraviolet region by the population inversion of the excimer, which is a diatomic molecule having a strong bond in the excited state. One example of processing conditions is a rare gas halide (KrF) as an oscillation line. Wavelength 248 nm, output energy density 3.3 J / cm ² , irradiation energy 0.8 J / c
m ² , etching rate 0.2 μm / pulse. As the processing dimensions, the width of the common ink chamber 28 is 120 μm, the depth is 40 μm, the diameter of the ink boiling chamber 27 is 100 μm, and the diameter of the nozzle hole 26 is 40 μm.

Nozzle member 23 obtained by the above steps
After the glass substrate 22 and the glass substrate 22 are aligned with each other, they are bonded by pressure and heating. If the adhesive is AS-60, a weight of 0.3-
The nozzle member 23 and the glass substrate 22 are bonded to each other by heating under a load of 0.5 kg / cm ² and 150 ° C. for 60 minutes. As a result, the protrusion of the adhesive on the joint surface can be reduced, and high-quality printing can be obtained.

As described above, according to the present embodiment, the adhesive resin layer is made of a flexible epoxy resin such as a modified urethane adhesive or a modified epoxy adhesive, and the insulating layer is made of a flexible ring. By using a synthetic rubber-based photosensitive resin, it is possible to increase the step difference absorption capability of the adhesive surface on the glass substrate, and to bond the nozzle member and the glass substrate with low weight, and to bond with a small amount of adhesive. Was able to improve. As a result, it was possible to reduce the protrusion of the adhesive into the ink boiling chamber and the common ink chamber.
Therefore, the conductive ink can be quickly replenished from the common ink chamber to the ink boiling chamber, the variation in the volume of the ink boiling chamber can be reduced, and the variation in the ink discharge pressure due to the generation of bubbles in the ink boiling chamber can be reduced. It was possible to improve the uniformity of ink droplets and the stability of the ejection amount. As a result, high resolution and high gradation printing quality can be obtained, and the reliability and mass productivity of the apparatus can be improved.

(Embodiment 2) FIG. 2A is a plan view of an essential part of a recording head according to a second embodiment of the present invention.
FIG. 2B is a sectional view of the main part of the recording head according to the second embodiment of the invention. In FIG. 2, 1B is a recording head according to the second embodiment of the present invention. 2 is an adhesive resin layer,
3 is an insulating layer, 22 is a glass substrate, 23 is a nozzle member, 2
4 is an electrode part, 26 is a nozzle hole, 27 is an ink boiling chamber, 2
Reference numeral 8 is a common ink chamber, 29 is an ink supply hole, and 32 is an external connection terminal. Since these are the same as those in FIG. 1 of the first embodiment or FIG. 4 of the conventional example, the same reference numerals are given and description thereof is omitted. The recording head 1B of the second embodiment is different from the first embodiment in that the side surface portion of the wiring portion 4a includes a bent portion 5 formed in a bent line shape, and the nozzle member 2 is provided.
3 can increase the bonding area between the glass substrate 22 and
It has the effect of improving the bonding strength.

As described above, according to the second embodiment, in addition to the effects of the first embodiment, the bonding area between the nozzle member 23 and the glass substrate 22 can be further increased, and the bonding strength can be improved. It was possible to improve the durability and reliability of the recording head.

(Third Embodiment) FIG. 3A is a plan view of a main portion of a recording head according to a third embodiment of the present invention.
FIG. 3B is a sectional view of a main part of a recording head according to the third embodiment of the invention. In FIG. 3, 1C is a recording head according to a third embodiment of the present invention. 2 is an adhesive resin layer,
3 is an insulating layer, 22 is a glass substrate, 23 is a nozzle member, 2
4 is an electrode part, 26 is a nozzle hole, 27 is an ink boiling chamber, 2
Reference numeral 8 is a common ink chamber, 29 is an ink supply hole, and 32 is an external connection terminal. Since these are the same as those in FIG. 3 of the second embodiment, the same reference numerals are given and description thereof will be omitted. The recording head 1C of the third embodiment is different from the second embodiment in that the upper surface of the wiring portion 4b has a configuration having a plurality of recesses 6, and the nozzle member 23 and the glass substrate 22 are different from each other. The bonding has an effect that the strength of adhesion can be improved by the anchor effect of the adhesive resin layer 2 by the plurality of recesses 6.

As described above, according to the third embodiment, in addition to the effect of the first embodiment, the nozzle member 23 and the glass substrate 22 are bonded to each other by the anchor effect of the adhesive resin layer by the plurality of recesses. As a result, the strength of adhesion can be improved, and the durability and reliability of the recording head can be improved.

[0023]

INDUSTRIAL APPLICABILITY As described above, the present invention has a flexible epoxy resin such as a modified urethane adhesive or a modified epoxy adhesive in the adhesive resin layer, and further has flexibility in the insulating layer. By using a cyclized rubber type photosensitive resin,
It is possible to reduce the protrusion of the adhesive into the ink boiling chamber or the common ink chamber, improve the uniformity of the ink droplets and the stability of the ejection amount, and obtain a recording head with excellent print quality and reliability. The advantageous effect that it can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a recording head according to a first embodiment of the invention.

FIG. 2A is a plan view of a main part of a recording head according to a second embodiment of the invention. FIG. 2B is a cross-sectional view of a main part of a recording head according to the second embodiment of the invention.

FIG. 3A is a plan view of a main part of a recording head according to a third embodiment of the invention. FIG. 3B is a cross-sectional view of a main part of a recording head according to the third embodiment of the invention.

FIG. 4A is a schematic plan view showing the structure of a conventional recording head. FIG. 4B is a schematic sectional view showing the structure of a conventional recording head.

FIG. 5A is a schematic plan view showing a protruding state of an adhesive in a conventional recording head. FIG. 5B is a schematic cross-sectional view showing a protruding state of an adhesive in a conventional recording head.

[Explanation of symbols]

 1A Recording Head of First Embodiment of the Present Invention 1B Recording Head of Second Embodiment of the Present Invention 1C Recording Head of Third Embodiment of the Present Invention 2 Adhesive Resin Layer 3 Insulating Layers 4a, 4b Wiring Part 5 Bending Part 6 Recessed part 21 Conventional recording head 22 Glass substrate 23 Nozzle member 24 Electrode part 25 Insulating layer 26 Nozzle hole 27 Ink boiling chamber 28 Common ink chamber 29 Ink supply hole 30 Adhesive resin layer 31 Wiring part 32 External connection terminal 33 Adhesive Overhanging part

Claims (3)

[Claims] 1. A nozzle member having a nozzle hole through which conductive ink is ejected and an ink boiling chamber in which the conductive ink boils, and bubbles are disposed in the conductive ink below the ink boiling chamber. A glass substrate having a pair of electrode portions to be generated, a wiring portion connected to the electrode portion, and an insulating layer covering the wiring portion, and an adhesive resin layer for joining the nozzle member and the glass substrate are provided. Recording head,
A recording head, wherein the adhesive resin layer is made of a thermoplastic epoxy resin or a modified urethane resin, and the insulating layer is made of a cyclized rubber photosensitive resin or a polycinnamic oxygen photosensitive resin. 2. The recording head according to claim 1, wherein a side surface portion of the wiring portion is formed in a bent line shape. 3. The recording head according to claim 1, wherein the upper surface portion of the wiring portion has a plurality of recesses.